Common Words:
* Kaffee (coffee)
* Kind (child)
* Kopf (head)
* Können (can, to be able to)
* Karte (card, map)
* Küche (kitchen)
* Kalb (calf)
* Katze (cat)
* Klasse (class, grade)
* Kino (cinema)
* Krankenhaus (hospital)
* Kugelschreiber (ballpoint pen)
Less Common Words:
* Kamel (camel)
* Kaktus (cactus)
* Käse (cheese)
* Kette (chain)
* Komma (comma)
* Krone (crown)
* Küsten (coast)
* Kleid (dress)
* Kunst (art)
* Kartoffel (potato)
* Knie (knee)
* Krieg (war)
* Kissen (pillow)
* Komödie (comedy)
* Kapitän (captain)
Bonus:
* Kaffee trinken (to drink coffee)
* Kinderwagen (stroller)
* Kopfschmerzen (headache)
* Königin (queen)
* Kalte Füße (cold feet)
* Kaffee kochen (to make coffee)
This is just a small selection, and there are many more German words beginning with K. If you're looking for words for a specific topic, please let me know and I can provide a more tailored list.